If I understood correctly what I've found searching around, a capability is "an unforgeable ticket, which when presented can be taken as incontestable proof that the presenter is authorized to have access to the object named in the ticket" (1). So there is an authority that gives a capability to an object, which in turn can pass the capability to some other trusted object ("Capabilities can be delegated" and "Capabilities can be copied" (2)).

When you need to access something, you must pass a ticket that will be verified on the other side; in other words, invoking a method is not sufficient, you need the right ticket.

There is still something unclear to me: who will issue tickets? Will an object request a ticket or the object itself will be created with some tickets?

HTH, Valerio

1) http://www.cap-lore.com/CapTheory/ProtInf/
2) http://www.eros-os.org/essays/capintro.html

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.